Pesticide compositions have been used in agrochemical and related applications. Pesticide compositions typically include an active ingredient as well as one or more adjuvants. In some applications, an active ingredient is a herbicide such as glyphosate. An example of a typical adjuvant is a surfactant. Pesticide compositions are disclosed in U.S. Pat. No. 4,690,775; U.S. Pat. No. 5,409,885; U.S. Pat. No. 5,512,534; U.S. Pat. No. 5,547,918; U.S. Pat. No. 6,093,681; U.S. Pat. No. 6,117,820; U.S. Pat. No. 6,200,586; U.S. Pat. No. 6,407,042; U.S. Pat. No. 6,770,612; U.S. Pat. No. 7,049,270; and U.S. Patent Application Publications No. 2005/0261130 A1 and No. 2007/0027034A1.
There are many kinds of pesticide compositions. For instance, conventional pesticide compositions may include a dispersion of spherulites or discontinuous drops of liquid crystal material. Such spherulites may be used to suspend a solid active ingredient as a dispersion. Other conventional pesticide compositions include aqueous mixtures and dispersions that may depend on lipophilic alcohol molecules. Such alcohols are not surfactants. Yet other conventional pesticide compositions may be an emulsion such as an emulsion of oil and water that may have liquid crystalline material at the oil/water interface. Such liquid crystalline material is a dispersed liquid crystal phase, and these emulsions are not in thermodynamic equilibrium. Further conventional compositions include a structured aqueous system that forms as a gel and may be precipitated as a second phase out of a first phase. Such system is a dispersion of liquid crystal material. Additional compositions include a gel obtained by centrifuging an emulsion system. These emulsions are not in thermodynamic equilibrium, and the gels are typically an isotropic gel. Generally, if a pesticide composition is isotropic it does not exhibit birefringence whereas if a pesticide composition is anisotropic it does exhibit birefringence. The arrangement of liquid crystals in a pesticide can affect birefringence.
Conventional surfactants typically form liquid crystals when highly concentrated above 40 w/w % surfactant. For example, conventional pesticide compositions may form anisotropic aggregates, or two-phase dispersions, of liquid crystals on a wax paper or plant surface (e.g., after spraying) when a solution such as a spray solution becomes highly concentrated in surfactant. This liquid crystal phase may form as discontinuous regions dispersed in a continuous isotropic concentrated spray solution. Such concentrated pesticide formulations are not birefringent homogeneous liquid crystals in a single thermodynamic equilibrium phase.
Drawbacks to conventional agrochemical compositions include that the surfactants are typically not formulated as a single-phase thermodynamic equilibrium liquid crystal. Multiple phase systems will have physical instabilities and can only be kinetically stable. Additional drawbacks to such agrochemical compositions include retention of the spray drops on the target surface and incomplete incorporation into the target pest. Further drawbacks include the limited time the active ingredient has to move into the pest due to the spray solution solidifying. Drawbacks to standard single-phase liquid crystal formulations include a high load of surfactant and high viscosity.
Consequently, there is a need for an improved agrochemical composition. Further needs include an improved pesticide composition that exists or has a thermodynamically stable homogeneous liquid crystal phase. Important needs for a liquid crystal formulation include both a relatively low surfactant concentration and a relatively low viscosity. Additional needs include a pesticide composition having improved retention and improved time for active ingredient diffusion.